@string{ iaprs = "International Archives of Photogrammetry, Remote Sensing, and Spatial Information Sciences" }
@string{ isprsannals = "ISPRS Annals of the Photogrammetry, Remote Sensing, and Spatial Information Sciences" }
@string{ PhotogrammRec = "Photogramm Rec" }
@string{ PhotogrammRecLong = "Photogrammetric Record" }
@string{ IntJCompVis = "Int J Comp Vis" }
@string{ IntJCompVisLong = "International Journal of Computer Vision" }
@string{ IJPRS = "ISPRS J Photogramm" }
@string{ IJPRSLong = "ISPRS Journal of Photogrammetry and Remote Sensing" }
@string{ PhotogrammetricEngineering = "Photogrammetric Engineering" }

@Article{Borlin2013:Experiments,
  seqno =	 815,
  author = 	 {Niclas B{\"o}rlin and Pierre Grussenmeyer},
  title = 	 {Experiments with Metadata-derived Initial Values and
                  Linesearch Bundle Adjustment in Architectural
                  Photogrammetry},
  journal = 	 isprsannals,
  year = 	 2013,
  volume =	 {II-5/W1},
  pages =	 {43-48},
  month = 	 sep,
  doi = {10.5194/isprsannals-II-5-W1-43-2013},
  keywords =	 {Bundle adjustment, convergence, initial values,
                  metadata, architectural photogrammetry},
  abstract =	 {According to the Waldhausl and Ogleby (1994) "3x3
                  rules", a well-designed close-range architectural
                  photogrammetric project should include a sketch of
                  the project site with the approximate position and
                  viewing direction of each image. This orientation
                  metadata is important to determine which part of the
                  object each image covers. In principle, the metadata
                  could be used as initial values for the camera
                  external orientation (EO) parameters. However, this
                  has rarely been used, partly due to convergence
                  problem for the bundle adjustment procedure.  In
                  this paper we present a photogrammetric
                  reconstruction pipeline based on classical methods
                  and investigate if and how the linesearch bundle
                  algorithm of Borlin et al. (2004) and/or metadata
                  can be used to aid the reconstruction process in
                  architectural photogrammetry when the classical
                  methods fail.  The primary initial values for the
                  bundle are calculated by the five-point algorithm by
                  Nist{\'e}r (Stewenius et al., 2006). Should the
                  bundle fail, initial values derived from metadata
                  are calculated and used for a second bundle attempt.
                  The pipeline was evaluated on an image set of the
                  INSA building in Strasbourg. The data set includes
                  mixed convex and non-convex subnetworks and a
                  combination of manual and automatic measurements.
                  The results show that, in general, the classical
                  bundle algorithm with five-point initial values
                  worked well. However, in cases where it did fail,
                  linesearch bundle and/or metadata initial values did
                  help. The presented approach is interesting for
                  solving EO problems when the automatic orientation
                  processes fail as well as to simplify keeping a link
                  between the metadata containing the plan of how the
                  project should have become and the actual
                  reconstructed network as it turned out to be.},
  haveit =	 {pdf}
}

@Article{Borlin2013:Bundle,
  seqno =	 817,
  author = 	 {Niclas B{\"o}rlin and Pierre Grussenmeyer},
  title = 	 {Bundle Adjustment with and without Damping},
  journal = 	 PhotogrammRecLong,
  year = 	 2013,
  volume =	 28,
  number =	 144,
  pages = 	 {396-415},
  month =	 dec,
  doi =          {10.1111/phor.12037},
  keywords =	 {adjustment, bundle, convergence, initial values,
                  least squares, terrestrial photogrammetry},
  abstract =	 {The least squares adjustment (LSA) method is studied
                  as an optimisation problem and shown to be
                  equivalent to the undamped Gauss-Newton (GN)
                  optimisation method. Three problem-independent
                  damping modifications of the GN method are
                  presented: the line search method of Armijo (GNA);
                  the Levenberg-Marquardt algorithm (LM); and
                  Levenberg-Marquardt with Powell dogleg (LMP).
                  Furthermore, an additional problem-specific "veto"
                  damping technique, based on the chirality condition,
                  is suggested. In a perturbation study on a
                  terrestrial bundle adjustment problem, the GNA and
                  LMP methods with veto damping can increase the size
                  of the pull-in region compared to the undamped
                  method; the LM method showed less improvement. The
                  results suggest that damped methods can, in many
                  cases, provide a solution where undamped methods
                  fail and should be available in any LSA software
                  package. Matlab code for the algorithms discussed is
                  available from the authors.},
  haveit =	 {pdf}
}

@Article{Haralick1994:Review,
  seqno = 384,
  author = 	 {Robert M. Haralick and Chung-Nan Lee and Karsten Ottenberg and Michael N{\"o}lle},
  title = 	 {Review and Analysis of Solutions of the Three Point Perspective Pose Estimation Problem},
  journal = 	 IntJCompVis,
  year = 	 1994,
  volume =	 13,
  number =	 3,
  pages =	 {331-356},
  abstract = {In this paper, the major direct solutions to the three
                  point perspective pose estimation problems are
                  reviewed from a unified perspective beginning with
                  the first solution which was published in 1841 by a
                  German mathematician, continuing through the
                  solutions published in the German and then American
                  photogrammetry literature, and most recently in the
                  current computer vision literature. The numerical
                  stability of these three point perspective solutions
                  are also discussed. We show that even in case where
                  the solution is not near the geometric unstable
                  region, considerable care must be exercised in the
                  calculation. Depending on the order of the
                  substitutions utilized, the relative error can
                  change over a thousand to one. This difference is
                  due entirely to the way the calculations are
                  performed and not due to any geometric structural
                  instability of any problem instance. We present an
                  analysis method which produces a numerically stable
                  calculation.},
  haveit = "pdf"
}

@Book{McGlone2004:Manual,
  editor =	 {Chris McGlone and Edward Mikhail and Jim Bethel},
  title = 	 {Manual of Photogrammetry},
  publisher = 	 {ASPRS},
  year = 	 2004,
  edition =	 {5th},
  month =	 jul,
  ISBN = {1-57083-071-1}
}

@InBook{Forstner2004:Analytical,
  seqno = {380:2},
  author =	 {Wolfgang F{\"o}rstner and Bernhard Wrobel and Fidel
                  Paderes and Robert Craig and Clive Fraser and John
                  Dolloff},
  title = 	 {Analytical Photogrammetric Operations},
  chapter = 	 11,
  publisher = 	 {IAPRS},
  year = 	 2004,
  edition =	 5,
  pages =	 {763-948},
  haveit = "pdf"
}

@Article{Stewenius2006:Recent,
  seqno = 270,
  author = 	 {Henrik Stew\'enius and Christopher Engels and David Nist\'er},
  title = 	 {Recent developments on direct relative orientation},
  journal = 	 IJPRS,
  year = 	 2006,
  volume =	 60,
  number =	 4,
  pages =	 {284-294},
  month =	 jun,
  keywords = {Relative orientation; Five-point method; Six-point method; Gr{\"o}bner basis},
  abstract = {This paper presents a novel version of the five-point
                  relative orientation algorithm given in Nister
                  [Nister, D., 2004. An efficient solution to the
                  five-point relative pose problem, IEEE Transactions
                  on Pattern Analysis and Machine Intelligence, 26
                  (6), 756--770]. The name of the algorithm arises
                  from the fact that it can operate even on the
                  minimal five-point correspondences required for a
                  finite number of solutions to relative
                  orientation. For the minimal five correspondences,
                  the algorithm returns up to 10 real solutions. The
                  algorithm can also operate on many points. Like the
                  previous version of the five-point algorithm, our
                  method can operate correctly even in the face of
                  critical surfaces, including planar and ruled
                  quadric scenes. The paper presents comparisons with
                  other direct methods, including the previously
                  developed five-point method, two different six-point
                  methods, the seven-point method, and the eight-point
                  method. It is shown that the five-point method is
                  superior in most cases among the direct methods. The
                  new version of the algorithm was developed from the
                  perspective of algebraic geometry and is presented
                  in the context of computing a Gr{\"o}bner basis. The
                  constraints are formulated in terms of polynomial
                  equations in the entries of the fundamental
                  matrix. The polynomial equations generate an
                  algebraic ideal for which a Gr{\"o}bner basis is
                  computed. The Gr{\"o}bner basis is used to compute
                  the action matrix for multiplication by a single
                  variable monomial. The eigenvectors of the action
                  matrix give the solutions for all the variables and
                  thereby also relative orientation. Using a
                  Gr{\"o}bner basis makes the solution clear and easy
                  to explain.},
  haveit = "pdf"
}

@article{Brown1971:Close-range,
   seqno = 75,
   author = "Duane C. Brown",
   journal = PhotogrammetricEngineering,
   number = 8,
   pages = "855--866",
   title = "Close-range camera calibration",
   volume = 37,
   year = 1971,
   abstract = {For highest accuracies it is necessary in close range
                  photogrammetry to account for the variation of lens
                  distortion within the photographic field. A theory
                  to accomplish this is developed along with a
                  practical method for calibrating radial and
                  decentering distortion of close-range cameras. This
                  method, the analytical plumb line method, is applied
                  in an experimental investigation leading to
                  confirmation of the validity of the theoretical
                  development accounting for variation of distortion
                  with object distance.},
   haveit = "pdf"
}

@Article{Borlin2014:Camera,
  seqno =	 835,
  author = 	 {Niclas B{\"o}rlin and Pierre Grussenmeyer},
  title = 	 {Camera Calibration using the Damped Bundle Adjustment Toolbox},
  journal = 	 ISPRSannals,
  year = 	 2014,
  volume =	 {II},
  number =	 5,
  pages =	 {89-96},
  month =	 jun,
  doi = {10.5194/isprsannals-II-5-89-2014},
  note = {Best paper award.},
  keywords =	 {Camera calibration, bundle adjustment, focal length,
                  convergent, initial values, close range
                  photogrammetry},
  abstract =	 {Camera calibration is one of the fundamental
                  photogrammetric tasks. The standard procedure is to
                  apply an iterative adjustment to measurements of
                  known control points. The iterative adjustment needs
                  initial values of internal and external parameters.
                  In this paper we investigate a procedure where only
                  one parameter - the focal length is given a specific
                  initial value. The procedure is validated using the
                  freely available Damped Bundle Adjustment Toolbox on
                  five calibration data sets using varying narrow- and
                  wide-angle lenses. The results show that the
                  Gauss-Newton-Armijo and Levenberg-Marquardt-Powell
                  bundle adjustment methods implemented in the toolbox
                  converge even if the initial values of the focal
                  length are between 1/2 and 32 times the true focal
                  length, even if the parameters are highly
                  correlated. Standard statistical analysis methods in
                  the toolbox enable manual selection of the lens
                  distortion parameters to estimate, something not
                  available in other camera calibration toolboxes. A
                  standardised camera calibration procedure that does
                  not require any information about the camera sensor
                  or focal length is suggested based on the
                  convergence results. The toolbox source and data
                  sets used in this paper are available from the
                  authors.},
  haveit =	 {pdf}
}

@Article{Borlin2016:External,
  seqno =	 877,
  author = 	 {Niclas B{\"o}rlin and Pierre Grussenmeyer},
  title = 	 {External Verification of the Bundle Adjustment in
                  Photogrammetric Software using the Damped Bundle
                  Adjustment Toolbox},
  journal = 	 iaprs,
  year = 	 2016,
  volume =	 {XLI-B5},
  pages =	 {7-14},
  month =	 jul,
  doi = {10.5194/isprs-archives-XLI-B5-7-2016},
  abstract = {The aim of this paper is to investigate whether the
                  Matlab-based Damped Bundle Adjustment Toolbox (DBAT)
                  can be used to provide independent verification of
                  the BA computation of two popular
                  software - PhotoModeler (PM) and PhotoScan (PS). For
                  frame camera data sets with lens distortion, DBAT is
                  able to reprocess and replicate subsets of PM
                  results with high accuracy. For lens-distortion-free
                  data sets, DBAT can furthermore provide comparative
                  results between PM and PS. Data sets for the
                  discussed projects are available from the
                  authors. The use of an external verification tool
                  such as DBAT will enable users to get an independent
                  verification of the computations of their
                  software. In addition, DBAT can provide computation
                  of quality parameters such as estimated standard
                  deviations, correlation between parameters, etc.,
                  something that should be part of best practice for
                  any photogrammetric software. Finally, as the code
                  is free and open-source, users can add computations
                  of their own.},
  keywords = {Software, Bundle adjustment, Accuracy, Quality, Best practice, Distortion, Data sets}}

@Article{Murtiyoso2017:Reprocessing,
seqno = 943,
AUTHOR = {A. Murtiyoso and P. Grussenmeyer and N. B{\"o}rlin},
TITLE = {Reprocessing Close Range Terrestrial and {UAV} Photogrammetric
Projects with the {DBAT} Toolbox for Independent Verification and
Quality Control},
JOURNAL = {ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences},
VOLUME = {XLII-2/W8},
YEAR = 2017,
PAGES = {171--177},
DOI = {10.5194/isprs-archives-XLII-2-W8-171-2017},
abstract = {Photogrammetry has recently seen a rapid increase in many
                  applications, thanks to developments in computing
                  power and algorithms. Furthermore with the
                  democratisation of UAVs (Unmanned Aerial Vehicles),
                  close range photogrammetry has seen more and more
                  use due to the easier capability to acquire aerial
                  close range images. In terms of photogrammetric
                  processing, many commercial software solutions exist
                  in the market that offer results from user-friendly
                  environments. However, in most commercial solutions,
                  a black-box approach to photogrammetric calculations
                  is often used. This is understandable in light of
                  the proprietary nature of the algorithms, but it may
                  pose a problem if the results need to be validated
                  in an independent manner. In this paper, the Damped
                  Bundle Adjustment Toolbox (DBAT) developed for
                  Matlab was used to reprocess some photogrammetric
                  projects that were processed using the commercial
                  software Agisoft Photoscan. Several scenarios were
                  experimented on in order to see the performance of
                  DBAT in reprocessing terrestrial and UAV close range
                  photogrammetric projects in several configurations
                  of self-calibration setting. Results show that DBAT
                  managed to reprocess PS projects and generate
                  metrics which can be useful for project
                  verification.},
keywords = {close range, UAV, bundle adjustment, quality control,
                  photogrammetry, software, DBAT}
}

@Article{Borlin2018:Modular,
  seqno = 963,
  author =       {Niclas B{\"o}rlin and Arnadi Murtiyoso and Pierre
                  Grussenmeyer and Fabio Menna and Erica Nocerino},
  title =        {Modular Bundle Adjustment for Photogrammeric Computations},
  journal =      iaprs,
  year =         2018,
  volume =       {XLII},
  number =       2,
  doi = {https://doi.org/10.5194/isprs-archives-XLII-2-133-2018},
  month = jun,
  pages =        {133-140},
  abstract = {In this paper we investigate how the residuals in bundle
                  adjustment can be split into a composition of simple
                  functions. According to the chain rule, the Jacobian
                  (linearisation) of the residual can be formed as a
                  product of the Jacobians of the individual steps.
                  When implemented, this enables a modularisation of
                  the computation of the bundle adjustment residuals
                  and Jacobians where each component has limited
                  responsibility. This enables simple replacement of
                  components to e.g. implement different projection or
                  rotation models by exchanging a module. The
                  technique has previously been used to implement
                  bundle adjustment in the open-source package DBAT
                  (Borlin and Grussenmeyer, ¨ 2013) based on the
                  Photogrammetric and Computer Vision interpretations
                  of Brown (1971) lens distortion model. In this
                  paper, we applied the technique to investigate how
                  affine distortions can be used to model the
                  projection of a tilt-shift lens. Two extended
                  distortion models were implemented to test the
                  hypothesis that the ordering of the affine and lens
                  distortion steps can be changed to reduce the size
                  of the residuals of a tilt-shift lens calibration.
                  Results on synthetic data confirm that the ordering
                  of the affine and lens distortion steps matter and
                  is detectable by DBAT. However, when applied to a
                  real camera calibration data set of a tilt-shift
                  lens, no difference between the extended models was
                  seen. This suggests that the tested hypothesis is
                  false and that other effects need to be modelled to
                  better explain the projection. The relatively low
                  implementation effort that was needed to generate
                  the models suggest that the technique can be used to
                  investigate other novel projection models in
                  photogrammetry, including modelling changes in the
                  3D geometry to better understand the tilt-shift
                  lens.},
  keywords = {Bundle adjustment, Camera model, Analytical Jacobians,
                  Software, Photogrammetry, Tilt-shift lens},
  haveit = "pdf"
}

@Misc{Foster2009:Calculating,
  author =       {Leslie Foster},
  title =        {Calculating the rank of sparse matrices using spnrank},
  howpublished = {http://www.math.sjsu.edu/singular/matrices/software/SJsingular/Doc/spnrank.pdf},
  month =        apr,
  year =         2009
}

@Article{Borlin2019:Flexible,
seqno = 1004,
  author =       {Niclas B{\"o}rlin and Arnadi Murtiyoso and Pierre Grussenmeyer and Fabio Menna and Erica Nocerino},
  title =        {Flexible Photogrammetric Computations using Modular
                  Bundle Adjustment},
  journal =      {Photogrammetric Engineering and Remote Sensing},
  volume =       85,
  number =       5,
  pages =        {361-368},
  month =        may,
  year =         2019,
  doi = {10.14358/PERS.85.5.361},
  abstract = {The main purpose of this paper is to show that
                  photogrammetric bundle adjustment computations can
                  be sequentially organized into modules. Furthermore,
                  the chain rule can be used to simplify the
                  computation of the analytical Jacobians needed by
                  the adjustment. Novel projection models can be
                  flexibly evaluated by inserting, modifying, or
                  swapping the order of selected modules. As a proof
                  of concept, two variants of the pin-hole projection
                  model with Brown lens distortion were implemented in
                  the open-source Damped Bundle Adjustment Toolbox
                  (DBAT) and applied to simulated and calibration data
                  for a non-conventional lens system. The results show
                  a significant difference for the simulated,
                  error-free, data but not for the real calibration
                  data. The current flexible implementation incurs a
                  performance loss. However, in cases where
                  flexibility is more important, the modular
                  formulation should be a useful tool to investigate
                  novel sensors, data processing techniques, and
                  refractive models.}
}

@Article{Borlin2019:Implementing,
  author =       {N. B{\"o}rlin and A. Murtiyoso and P. Grussenmeyer},
  title =        {Implementing Functional Modularity for Processing of
                  General Photogrammetric Data with the Damped Bundle
                  Adjustment Toolbox (DBAT)},
  journal =      iaprs,
  year =         2019,
  volume =       {XLII},
  number =       {2/W17},
  pages =        {69-75},
  month =        dec,
  doi = {10.5194/isprs-archives-XLII-2-W17-69-2019},
  keywords = {open-source software, bundle adjustment, flexible
                  computations, photogrammetry},
  abstract = {The Damped Bundle Adjustment Toolbox (DBAT) is a free,
                  open-source, toolbox for bundle adjustment. The
                  purpose of DBAT is to provide an independent,
                  open-source toolkit for statistically rigorous
                  bundle adjustment computations. The capabilities
                  include bundle adjustment, network analysis, point
                  filtering, forward intersection, spatial
                  intersection, plotting functions, and computations
                  of quality indicators such as posterior covariance
                  estimates and parameter correlations. DBAT is
                  written in the high-level Matlab language and
                  includes several processing example files. The input
                  formats have so far been restricted to PhotoModeler
                  export files and Photoscan (Metashape) native files.
                  Fine-tuning of the processing has so far required
                  knowledge of the Matlab language. This paper
                  describes the development of a scripting language
                  based on the XML (eXtensible Markup Language)
                  language that allow the user a fine-grained control
                  over what operations are applied to the input data,
                  while keeping the needed programming skills at a
                  minimum. Furthermore, the scripting language allows
                  a wide range of input formats. Additionally, the XML
                  format allows simple extension of the script file
                  format both in terms of adding new operations, file
                  formats, or adding parameters to existing
                  operations. Overall, the script files will in
                  principle allow DBAT to process any kind of
                  photogrammetric input and should extend the
                  usability of DBAT as a scientific and teaching tool
                  for photogrammetric computations.}
}
